No description available.

No / The heat balance integral method is a familiar technique for treating transport problems, particularly phase-change scenarios. Here a number of differences arising in the method's implementation are investigated that result in quantitatively distinct solutions. As a consequence some guidance is provided for selecting the appropriate implementation of the method.

The presence of a blockage in a pipeline will alter the fluid dynamics of a flowing system in terms of the heat, mass and velocity characteristics. The analysis of the fluid dynamics is based on balances taken on the overall system to qualitatively and quantitatively assess the effects of the blockage. Pioneer work in the area of mass and momentum effects of blockages led to the development of blockage type curves useful in characterizing blockages from limited information. This work is an extension of previous work and is based on the application of a simplistic energy balance approach to characterize blockages in pipelines. The resulting heat models for the case of both a partially and fully-blocked flowline correctly predict the effect of wax deposition. Dimensionless temperature-based blockage maps developed here can be used in modeling unique cases where only two of the three necessary conditions are given. The heat model matches results from commercial software within a limited range of restricted flow conditions.

The structure of old monumental churches differs a lot from contemporary buildings. The structural materials were wood, brick and stone. In order to construct high buildings with huge spans, thick massive walls and many massive columns were needed. Originally these buildings had no heating and for centuries the outdoor temperature determined the indoor climate. As churches are considered historical heritage buildings their renovation should be thoroughly studied.               In this thesis the transmission losses of Hamrånge church will be analysed. Hence, the transmission trough walls and windows as well as the heat buffering of materials will be examined. In addition, the effect of possible reformation measurements will be concluded.               Finally, this project belongs to a complete study of the church, were not only transmission losses are considered but also air infiltration losses and solar heat gain. That way, a comparison between them will be carried out in order to contribute to attain the objective of the project: possible restoration for church heating system with respect to preservation, energy requirements, thermal comfort and aesthetics. / Church project

No / Convergence properties are established for the piecewise linear heat balance integral solution of a benchmark moving boundary problem, thus generalising earlier results [Numer. Heat Transfer 8 (1985) 373]. A convergence rate of O(n¿1) is identified with minor effects at large values of the Stefan number ß (slow interface movement). The correct O(n¿1/2) behaviour for incident heat flux is recovered for ß ¿ 0 (pure heat conduction) as previously found [Numer. Heat Transfer 8 (1985) 373¿382]. Numerical illustrations support the theoretical findings.

Thermoregulation is considered a top priority in neonatology due to the fact that relative to adults, neonates have a morphological susceptibility to excessive heat exchange with the environment, and exhibit limited physiological/behavioural responses to thermal strain. Consequently, the environmental conditions in which they are nursed must be tightly regulated to maintain body temperature stable. Neonatal intensive care units (NICU) use radiant warmers (RW) to thermally manage many newborns. However, recent evidence suggests that RW induce intermittent bouts of thermal strain that could adversely affect patients. This warrants further investigation of neonatal heat balance and the pertinent factors affecting it. Conducting an exhaustive audit of heat exchanges affecting the body during standard care under a RW could yield important information that would lead to the improvement of clinical practice in NICUs. The present thesis focuses on neonatal thermoregulatory responses, various body heat exchange mechanisms and processes during standard care under RW.

This thesis presents a series of studies into the responses of people to outdoor thermal conditions experienced over all seasons in the United Kingdom. The aim was to investigate practical methods for predicting human responses to outside weather conditions, which would be useful in predicting effects on human comfort and health. The studies involved both laboratory experiments and field trials. One particular aspect of outside conditions, not usually investigated in laboratory studies, is the contribution of solar radiation. Single subject and thermal manikin studies were used to determine the contribution of solar radiation to human response. In addition to this, a total of 168 subjects responses were recorded during trials at the Loughborough University weather station compound. (latitude 52.47N and longitude 01.11W). The trials were distributed between July 2007 and October 2008. This provided a comprehensive data-base for the evaluation of thermal indices. The thesis is divided into four parts. Part one provides an introduction to the subject and a comprehensive literature review. It also describes equipment, calibration procedures and methods used. Part two quantified the contribution of solar radiation to the heat load on a person. A human subject and a heated thermal manikin were exposed to outdoor thermal conditions, while in light clothing and (for the person) conducting a step test. They were then exposed to identical conditions in a thermal chamber, but without the contribution of the sun. The conditions outside were 23˚C air temperature, 42˚C mean radiant temperature and 54% relative humidity with an average air velocity of 0.75 ms-1. The difference in sweat rate (person) and heat required (manikin) between outdoor and indoor conditions were used to estimate the contribution of the sun. Using three different analyses estimates were 14 Wm-2, 35 Wm-2 and 50 Wm-2 depending upon the assumptions made. Part three describes current thermal indices that can be used to assess the effects of weather conditions on people. It also presents the results of weather station measurements over the time period considered. In chapters 8 and 9 field trials are described which capture both the thermal conditions and human physiological and subjective responses to those conditions. Chapter 10 uses the data collected to provide an evaluation of current thermal indices for predicting human responses. The range of air temperature and relative humidity (at 2 pm) over a year was -2˚C to 29˚C and 34% to 95% respectively. Wind speed varied and was greater in winter and spring than in summer and autumn. Solar radiation was influenced by the altitude of the sun which depended upon season. Mean solar radiation increased from December to June and decreased from June to December. The subjective and physiological responses for 130 people (65 males and 65 females) over a range of outdoor weather conditions are presented. Physiological responses for females generally showed a stronger relationship with environmental variables and subjective responses than those for males. The subjective and physiological responses of four groups (one in each season of the year - involving a total of 38 people), are presented. It was found that there were significant individual differences in response. Part four provides a suggestion for an improved thermal index. The PMV (Predicted Mean Vote) out of four thermal indices (WBGT, PMV, WCI/tch and Twc) had the strongest relationship with environmental variables and physiological responses but had a weak relationship with subjective responses. A PMVoutdoors index was developed to improve the prediction of subjective responses for the outdoor conditions investigated. Conclusions and recommendations for future research are provided.

Thermoregulation is considered a top priority in neonatology due to the fact that relative to adults, neonates have a morphological susceptibility to excessive heat exchange with the environment, and exhibit limited physiological/behavioural responses to thermal strain. Consequently, the environmental conditions in which they are nursed must be tightly regulated to maintain body temperature stable. Neonatal intensive care units (NICU) use radiant warmers (RW) to thermally manage many newborns. However, recent evidence suggests that RW induce intermittent bouts of thermal strain that could adversely affect patients. This warrants further investigation of neonatal heat balance and the pertinent factors affecting it. Conducting an exhaustive audit of heat exchanges affecting the body during standard care under a RW could yield important information that would lead to the improvement of clinical practice in NICUs. The present thesis focuses on neonatal thermoregulatory responses, various body heat exchange mechanisms and processes during standard care under RW.

Thermoregulation is considered a top priority in neonatology due to the fact that relative to adults, neonates have a morphological susceptibility to excessive heat exchange with the environment, and exhibit limited physiological/behavioural responses to thermal strain. Consequently, the environmental conditions in which they are nursed must be tightly regulated to maintain body temperature stable. Neonatal intensive care units (NICU) use radiant warmers (RW) to thermally manage many newborns. However, recent evidence suggests that RW induce intermittent bouts of thermal strain that could adversely affect patients. This warrants further investigation of neonatal heat balance and the pertinent factors affecting it. Conducting an exhaustive audit of heat exchanges affecting the body during standard care under a RW could yield important information that would lead to the improvement of clinical practice in NICUs. The present thesis focuses on neonatal thermoregulatory responses, various body heat exchange mechanisms and processes during standard care under RW.

The independent influence of maximum oxygen consumption (VO2max) and running economy (RE) on thermoregulatory responses during treadmill exercise have not been isolated due to the complex interactions between VO2max, RE, body mass, body surface area (BSA), and metabolic heat production (Hprod). The purpose of the thesis is to determine whether large differences in VO2max and/or running economy independently alter thermoregulatory responses during running in a neutral environment. Seven aerobically unfit (LO-FIT: ~ 40 mlO2·kg-1·min-1) and sevn aerobically fit (HI-FIT: ~ 60 mlO2·kg-1·min-1) males, matched for body mass and BSA ran at 1) a fixed metabolic heat production of 640 W (FHP trial) and 2) 60%VO2max (REL trial). Also, seven high RE (HI-ECO: ~ 185 mlO2·kg-1·km-1) and seven low RE (LO-ECO: ~ 220 mlO2·kg-1·km-1) males, matched for body mass, BSA and VO2max (~ 60 mlO2·kg-1·min-1) ran at a 1) fixed Hprod of 640 W (FHP trial) and 2) fixed running speed of 10.5 km·h-1 (FRS trial). All trials were performed in a thermoneutral environment. The data was analyzed using a two-way mixed ANOVA, with the significance level set at an alpha of 0.05 for all comparisons. It was hypothesized that thermoregulatory responses (i.e., core temperature and sweating), during exercise will not be independently altered by VO2max, but will be altered by any differences in heat production and running economy. The FHP trial resulted in similar changes in esophageal temperature (∆Tes), changes in rectal temperature (∆Tre), and WBSL between the HI-FIT and LO-FIT groups, despite vastly different %VO2max. Whereas the REL trial resulted in greater ΔTeso, ΔTre, and WBSL in the HI-FIT group, in parallel with their greater Hprod. In groups greatly differing in RE, the FHP trial elicited similar ∆Tes, ∆Tre, and WBSL; however the HI-ECO group had to run faster to achieve the same heat production as their LO-ECO counterparts. Moreover, a FRS of 10.5 kmh-1 produced a greater Hprod, ∆Tes, ∆Tre, and WBSL in the LO-ECO group. In conclusion, thermoregulatory responses are determined by Hprod and RE, not VO2max, when differences in mass and BSA are eliminated between groups. Thus, these findings support the initially stated hypotheses.